Process for preparing 1,4-bridged cyclohexane carboxylic acid derivatives

Abstract

A process for preparing a compound of Formula (I): ##STR1## wherein R is phenyl or phenyl substituted with hydroxy, lower alkoxy, halogen or lower alkyl; Y is unsubstituted or substituted methylene, ethylene, vinylene or oxygen; m is 0 or 1; n is 0, 1 or 2; and q is 1, 2, 3 or 4; with the limitation that when m is 0, n is not 0, and when m is 1, n is not 2, which process comprises: (a) reacting an aldehyde of Formula (II); ##STR2## wherein R, Y, m and n are as defined above, under reaction conditions for the Wittig Reaction with a ylide of Formula (III): (R.sup.1).sub.3 P═CH(CH.sub.2).sub.q COOM (III) wherein R 1 is C 1 -C 8 alkyl or aryl, M is an alkali metal and q is as defined above; (b) treating the reaction mixture of step (a) with an alkaline earth metal halide under alkaline conditions to form the alkaline earth metal salt of the carboxylic acid of Formula (I); (c) extracting the alkaline earth metal salt of the carboxylic acid of Formula (I) in an organic solvent; and (d) recovering the free carboxylic acid of Formula (I) from the organic solvent.

What we claim is: 
     
       1. A process for preparing a compound of Formula (I): ##STR11## wherein R is phenyl or phenyl substituted with hydroxy, lower alkoxy, halogen or lower alkyl; Y is unsubstituted or substituted methylene, ethylene, vinylene or oxygen; m is 0 or 1; n is 0, 1 or 2; and q is 1, 2, 3 or 4; with proviso that when m is 0, n is not 0, and when m is 1, n is not 2, which process comprises: (a) reacting an aldehyde of Formula (II); ##STR12##  wherein R, Y, m and n are as defined above, under reaction conditions for the Wittig Reaction with a ylide of Formula (III):   (R.sup.1).sub.3 P═CH(CH.sub.2).sub.1 COOM              (III)     wherein R 1  is C 1  -C 8  alkyl or aryl, M is an alkali metal and q is as defined above;     (b) treating the reaction mixture of step (a) with an alkaline earth metal halide under alkaline conditions to form the alkaline earth metal salt of the carboxylic acid of Formula (I);   (c) extracting the alkaline earth metal salt of the carboxylic acid of Formula (I) in an organic solvent; and   (d) recovering the free carboxylic acid of Formula (I) from the organic solvent.   
     
     
       2. The process of claim 1 wherein the reaction mixture of step (a) is extracted with water and the aqueous extract is used in step (b) in place of the reaction 
     
     
       3. The process of claim 1 wherein the alkaline earth metal halide is magnesium, calcium or barium halide. 
     
     
       4. The process of claim 1 wherein the organic solvent is ethyl acetate. 
     
     
       5. The process of claim 1, wherein the alkaline earth metal halide is calcium halide and the organic solvent is ethyl acetate.